1. Technical Field
The present invention relates to a feed drive device for a printer for feed-driving a print medium, such as a printing tape, in synchronization with drive of a print head, and also relates to a printer.
2. Related Art
Feed drive devices of the above-described type have been known to have a feed roller that feeds a printing tape in synchronization with drive of a print head, a drive motor constituting a driving source of the feed roller, and a roller reduction gear train that transmits power from the drive motor to the feed roller. JP-A-2003-237155 is an example of related art. The drive motor includes a DC motor, and the main shaft of the drive motor is provided with an encoder.
In use of such a feed drive device, when stopping feed drive, the feed roller slightly reversely rotates. Specifically, when stopping feed drive, elastic deformation of the feed roller or the action of a spring for preventing reverse rotation of the printing tape, for example, causes the feed roller to slightly rotate in a direction opposite to the feeding direction of rotation. Such reverse rotation of the feed roller causes a problem that after stopping printing for a while and cutting the printing tape, a printing position shifts when printing is started again, and therefore, desired printing cannot be performed. One possible approach for solving such a problem is to incorporate a one-way clutch for preventing reverse rotation in the feed roller. However, reverse rotation due to “idle” that the one-way clutches have cannot be avoided. There is another problem such as an increase in costs.